Diablo III's real-money auction house had some potential to be a major innovation in virtual economies. Instead, it looks like the designers failed to grasp lessons of virtual money management that are now more than a decade old. Namely, make sure you have enough sinks.
There's a wonderful, well-informed, economically expert write-up over at Mises.Org, by Peter C. Earle. Mr. Earle knows his econ and he knows the game as well. It's some of the best virtual economy analysis I ahve seen in a long while.
Thanks to Waiyen Tang for the heads-up!